In order to meet the growing demand for living donor kidneys, the inclusion criteria for prospective donors have become less selective, allowing previously ineligible patients to donate kidneys. One donor group that has become increasingly more utilized is the overweight patient. There is substantial evidence that overweight individuals are more susceptible to the development of renal disease either as a direct result of their weight or as a consequence of their obesity-related co-morbidities such as diabetes and hypertension. In addition, it appears that even mild renal dysfunction can increase the risk of developing cardiovascular (CV) disease, which is already more common in this population. Despite these findings, very little is known about the individual and interactive effects of obesity and donation on the overall health of kidney donors. Our study addresses some of these questions by examining the effects of obesity on long-term renal function and development of cardiovascular risk factors such as hypertension, dyslipidemia, and metabolic syndrome in patients who donated a kidney at the University of California, San Francisco (UCSF) more than 5 years ago (1967-2002). The UCSF database consists of more than 2500 donors, 1949 of which fit into this category. The control group (n=978) will comprise of all potential kidney donors at UCSF during this period who passed an initial medical screening evaluation but did not donate because they were found to be ABO- or crossmatch incompatible. Using an accurate internet-based search protocol, we have been able to identify the current addresses and telephone numbers of more than 85% of the donors and 2 kidney controls, and have initiated recruitment for participation in our study. We believe that the results of the proposed study will be important in developing more precise guidelines for the selection and long-term health care maintenance of kidney donors. PUBLIC HEALTH RELEVANCE: Relevance Statement This proposal examines the impact of obesity on long-term renal function and development of hypertension and other risk factors for cardiovascular disease in patients who donated a kidney at the University of California, San Francisco. We believe that the results of the proposed study will be important in developing more accurate guidelines for the selection and long-term health care maintenance of kidney donors.